posted
I wouldn't recommend using regular silicone as an adhesive on foam, there are silicone adhesives that will work a lot better. Silicone 'caulk' is just that, a crack filler, it will bond to some surfaces but not real good to foam. I take it these will be 24" or so letters on aluminum sheet. If the panels are already installed and your putting the letters on, then I would use 'liquid nails' (a construction adhesive). If you plan to put the letters on the panels then install you may have problems with the letters popping off because of the flexing of the 8' sheets. You may want to drill through the back of the aluminum and place some galvanized deck screws into each letter in several places. This doesn't provide much 'pull strength' but will provide good 'shear strength'. Place a little of the construction adhesive in the drilled hole and the screws will carry the adhesive down into the foam. BTW, did you tell the customer that foam is a very temporary type sign.
------------------ Larry
Elliott Design McLemoresville, Tn.
If you can't find the time to do it right, where gonna find the time to do it over?
Posts: 486 | From: McLemoresville, TN. USA | Registered: Nov 1998
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Fill us in on the type of foam you are using, the height and thickness of the letters.
and Larry, Larry, Larry, please consider giving foam another chance. We have foam letters and graphics installed all over town and some have been around for nearly 15 years. Ample primer and paint is a major factor in it's longevity. All of our foam letters and graphics are applied with 100% Silicone Rubber Sealant, clear. Applied to aluminum or otherwise. Foam is suceptable to vandalism, but really what isn't!
We love working with foam! Cher.
------------------ Cheryl Lucas a/k/a "Shag" on MIRC Vital Signs & Graphics, Etc. Cape Coral, Florida VSignsNgraphics@aol.com
Posts: 987 | From: Cape Coral, FL USA | Registered: Aug 2000
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posted
Thanks for replying guys. I like the idea of the deck screws, Larry. Cheryl, the letters are 29"x4" of the regular beady type foam. As you said about the 100% silicone, I've had great results with the one Gemini used to sale, but as I just mentioned, its no longer available.(plus I've only used it on cement, not aluminum) Now that Larry mentions about foam being temp, how long should I expect these to last? We have foam letters that have been up for over 2 years now (facing south) & so far look good.
------------------ Marcano-Welch Signs Luquillo, Puerto Rico 787-889-6608
Posts: 2287 | From: Luquillo, Puerto Rico, USA | Registered: Nov 2000
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posted
I've also heard that birds like to pick at foam. A solution might be to encase the foam in Pierre's Pelucid. That tough stuff would give the birds a real beak ache.
Also, I would check carefully into constuction adhesive for exterior use. I brought up using that stuff outdoors and was told it is NOT an exterior adhesive. This was advice from one Letterhead, not from the manufacturer but I would still check it out before using it.
------------------ Dave Sherby "Sandman" SherWood Sign & Graphic Design Crystal Falls, MI 49920 906-875-6201 ICQ: 21604027 sherwood@up.net
posted
I can ditto the part about not trusting silicone adhesives. After a major failure where the plastic faces fell off their foam backers, we ran a samples using every brand of silicone adhesive that was in our store. That included the GE2000 stuff, the Gemini stuff, and various brands picked up at the local hardware store. We backed acrylic with vinyl and then siliconed the vinyl to foam. We found that some silicones were very aggressive and others had no grip at all. There appeared to be no rhyme or reason to what worked and what did not.
I would echo the recommendation about getting a mechanical fastener in there somewhere to help the glue. Vic G
------------------ Victor Georgiou Bob Loves Signs Inc Danville, CA email blssign@pacbell.net
Posts: 1746 | From: Danville, CA , USA | Registered: Dec 1998
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posted
Hey Felix, I made my own sign this way: I did a 1" tube stock with an extruded metal frame, hand carved foam letters, stud mounted into the aluminum face. The studs are easy to set in the back of the letters, just drill holes in the back of the letter,bigger than the studs, fill with WEST System epoxy and set studs, I use machine screws, right into the epoxy. stud mounting sheet stock is good because you can put nuts on the back.... "ain't neva gonna come off...gaarunteeed"
------------------ -------------------------------------------------- "A wise man once said that, or was it a wise guy?"
posted
I rarely use styrofoam for letters, but there is a set I did in '92 that are on a wall with southern exposure that still look just fine. I remember I gave them 2 coats of acrylic (Frazee) paint. They're about 25 feet up on a wall, out of the way of peoples hands, etc. I put them on a cement block wall with double side tape and quality silicone.
posted
Cheryl, Cheryl, Cheryl I do give foam a second chance. I've used it for several projects but it is still a temporary material of choice, especially the closed-cell styrofoam type. Construction insulation foam is a little better and the HDU type is as good as it gets.
Maybe in the areas that don't get temperature extremes from below zero to over 100 degrees you can get a little more life out of foam but where my business reputation is on the line I won't use it without telling the client it is only an economical temporary solution. Most of the cost of the letters is in the design, cutting, prepping, painting and installation, differences in material cost is only a very small part of the overall project. Extra coats of primer and paint along with the labor to make foam a permanent material will outweigh the savings of the materials 'cause as we all know,,,, 'Time is Money'. Oh, and I love working with foam too, what else is any more enjoyable than trying to sweep up the dust or get the little balls of foam off everything in the shop. You could also use sheetrock (Gypsum Board) or cardboard for exterior signs,,,,, If,,, you put enough paint on it!
------------------ Larry
Elliott Design McLemoresville, Tn.
If you can't find the time to do it right, where gonna find the time to do it over?
Posts: 486 | From: McLemoresville, TN. USA | Registered: Nov 1998
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posted
I have to agree with Cheryl's post. Well primed and painted foam will last a long time. And I have neve lost a letter due to silicone installation. Right across the street I have 24" stylite letters adhered to a corrugated aluminum front. After 4 years no deterioration or unsecure letters and they only have certain points contacting the high points of the aluminum. Now I wouldn't normally recommend this, I was even iffy on that one. I have had some foam letters break down, to my detriment, but that was due to insufficient painting on my part. This all said, foam letters are still considered second rate signage when I sell. Gemini letters are what I always recommend and if you buy foam, consider you get what you pay for.
------------------ Wright Signs Wyandotte, Michigan Since 1978 http://www.wrightsigns.bigstep.com
Posts: 2786 | From: Wyandotte, MI USA | Registered: Jan 1999
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posted
OK Guys, Learn this, if you use 2# styrofoam ®, 2" thick and Painted with Sherwin Williams DTM(direct to metal) Acrylic,3 coats. And Apply with Dow ® 732 Silicone it will last outdoors(excluding vandalisim) 10 to 20 years. Foam takes 500 years to degrade in the dump. but will degrade from weather wind storms and hail. I have been making foam letters since 1980 and some of them are still up. But most of them outlasted the business they were made for. Birds do pick on foam if it is not painted well. also the backs of foam should be totally covered with a thin layer of silicone when installed. But Don't paint them. If you use silicone on aluminum panels, make sure the panel is painted with a paint that will not be dissolved by the silicone, and you won't have a problem.As far as screwing through aluminum panels, It is not necessary or helpful. As the silicone will flex with temp changes, the screws will only cause seperation. A note of caution, I only guarantee my work and procedures, not yours. LOL Bill
------------------ Bill & Barbara Biggs Art's Sign Service, Inc. Clute, Texas, USA Home of The Great Texas Mosquito Festival Proud Third year Supporter of the Letterheads Website MailTo:twobeesusa@netscape.net
Posts: 1020 | From: Lake Jackson,Tx | Registered: Nov 1998
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